Apparatus for feeding mechanical grinding machines for producing wood pulp



tum-. STATES PATENT OFFICE;

; alone Nansen, or nnnrscnnonr, Nana wazamsnumr, enmity.

' minim non r'nnnme mechan cs; enmnme macnntnsr'on rnonucnte woon -PUL1.

' Application. filed April e, 1925, Serial No.

This invention relates to an apparatus for feedin mechanical grinding machines for producing wood pulg t p M One object of the invention is to enable 5 in' the operation of a mechanical grind ng mac hin'e a given ratio between the driving powerand the specific pressure exerted on 4 the grinding elements to be maintained and adjusted, in order firstly to be. able to utilize 1 practically all the" power available at the grinding shaft under variable conditions of worki and secondly to obtain a wood pulp of uni'orm good quality.

- A further object of the invention is to provide ap aratus as above-mentioned in which rotary odies with s irally formed surfaces are employed as fee ingmembers for pressingforward the wood pile.

In order to be able to maintain a given ratio between the driving power of the grind stone and the pressure exerted on the wood- 'pile which is pushed forward by the feedmg members, thedrivin of one or more feedin members takes p ace 1 means of a B5 variab e transmissiongear pre erably a hydraulic couplin having avariable slip, so

that the transmission ratio may be changed in' accordance. therewith. The variation of thet'ran's'mission ratio is efiected by means of a regulating device the action of which on said hydraulic transmission gear is controlled ,by the actual speed of the grinder shaft or the loading of the driving engine,

so that with an increased number. of'revoluac tions the s 'eed of the feedin members is increased. e pressure of tfie woodv against the grind stone is consequently also increased and the increased rotary power ofthe grind stone is rendered available for pro- 40 ducmg a considerably eater quantity of 'wood pulp. This re F sting arrangement may also s employ in continuous grinders in which the feeding of the wood pile is effected by means of feedin members hava construction which spiral rotary bodies above mentioned.

As a regulating member to obtain as infinite a variation as possibleof the ratio of thetransm lission gear or the slip ofthe coupling, a ceritrifugal governog may "be employeddirectlydriven from, shaft ofthe grinder, \Itegulating devices may also be ifl'ers from the areas, mun eelan February 4, 1925.

dependent on the load-on theen 'ne or by means of an electriccurrent whic efiects a constant alteration of the transmission gear The hydraulic transmission device itself is preferably formed as a liquid coupling.

used which are otherwise influenced, accord- Instead thereof the power may also be trans-' 1 mitted by means of gas or steam acting withinthe coupling. As'a liquid -coupling any coupling ma ,e used which in its. construction is simi air to the ordinary known hydraulic brakes as will-be more particularly set forth in the detailed ex lanation illustrated by a drawing hereina er set forth.

If a' mechanical transmission be selected;

a diiferential gear is preferably used, where f in one of the three members is coupled with I a the axles of the feeding members and the's'ecend with the drive of the grinding machine, Y

whilst the third member of said gear is engaged by a liquid brake, the slip of which.

is controlled by a governor.

In addition to this automatic equalization between rotary power and pressure which facilitates the utilization of fluctuations of" power arising in the operation ofv the grind ing drive as a further feature of this Invention in the, apparatus serving for feeding the grinder, suitable means are providedto enable the total pressure exerted on the grind stone to be adjusted within the widest limits and thus'to be adapted to the wide fluctuations such as areproduced more a-rticularly in the case of grinders operated by water power by the varying weather conditions. 1

Also in the case of substantially dimin- 'ished driving power it ism necessary for the production of a uniformly good wood pulp to allow the grind stone town at a glven minimum speed. In-orde'r togallow of this,

as a. further feature of the invention, the

limits ofthe shaft formed by the feeding members and the walls are adjustable so that the size of the grinding surface can be adjusted to correspond withthe amount of driving power at any time available. The.

specific pressure nry forprod'ucing a I good wood pulp ma exist over the diminished grinding sur ace without the grind stone being in conse uenoe reduced to an inadmissible low spee The mounting of the conveying members according to this invention is carried out so that they are resiliently supported and so that the feeding members at pressures unsuitable for utilization against the wood pile can yield somewhat. The object of this is to prevent the lateral pressures exerted on the feeding members which for instance may be caused by contact with a hard piece of wood, being directly transmitted to the walls of the conveyor shaft.

An example of construction of the improved arrangement for mechanical power inders is illustrated in the accompanying iagrammatic drawing showing .an elevation partly in section.

The wood is conveyed in a shaft 1 against a grind stone 2, by means of rotary bodies 3 having spirally formed surfaces. These rotary bodies are driven by means of worm wheels 4 and worms 5. The upper bearings 6 of the rotary bodies 3 are arranged for pivotal movement about the axis of the re spective worms 5. The lower bearings 7 are resiliently supported by means of springs 8.

The driving worms 5 and the spring su ports 8 are mounted in the frame 9, tie space between said worms being adjustable by means of the threaded spindle 10 which is guided by the nuts 21 fastened on the bearings 22 of the worm 5. The spindle 10 is provided with a left-hand and a right-hand thread on opposite ends thereof.

The'worm 5 is driven by means of a worm gear from the rotor 15 of a hydraulic slip coupling. This slip coupling resembles in construction the well-known hydraulic brake, which is used for imposing a load upon engines or other prime movers espeorally for the urpose of measuring the power thereof.

his brake or slip cou ling consists of the cylindrical rotor 15, which is rotatably mounted within the rotatable hollow cylinder 11. The circumferential surfaces of the two cylinders 11 and 15, which are facing each other, are equipped with rojections, such as pins or ribs 13 and 14. he outer rotor or cylinder 11 is provided with an interior rim and a pipe 18 for conveying a liquid, preferably oil, to said outer rotor 11 projects into the latter. If now liquid is passed into the outer rotor 11, while" thelatter is rapidly rotated the said liquid 9 will be distributed in the form of a ringshaped layer over the interior circumference of the rotor 11. The liquid will be carried with the pins'13 which are rovided on the rotor 15, so that said liqui' will act upon the pins 14, thus carrying the interior rotor 15 with it.- The interior rotor 15 will thus follow the rotation of the outer rotor 11 *at .slip coupling and -regulatin a somewhat smaller speed, so that a certain slip will exist between the individual speeds of the rotors. This slip will be increased, if the quantity of the oil rotatin the rotors and therewiththe thic ness of the ring-shaped la er of oil is decreased.

within The outer cylin er or rotor 11 is rotated by means of any suitable driving means from the axle 12 of the grinding machine, said driving means being for the sake of convenience not shown in the drawing. The rotor 11 is preferably turned or ground off on its outer peripheryin such a manner that it may be used as a pulley. The centrifugal governor 16 is likewise driven from the axle the speed of rotation of the grinding stone.v

I declare that what I claim is:

1. In a wood inding machine the com bination of a grinding stone, with .feedin members for feeding a charge of woo blocks to said grinding stone said feeding members forming sidewalls for the char e containing feeding space or shaft of t e grindingmachine, and means for adjustin the distance between the lower' ends of sai feedin members for the purpose of varying the e ective contact surface between the charge and said grinding stone.

2. A wood grinding machine, as specified by claim 1, having at least one of the feeding members provided with an upper bearing arranged for pivotal movement of said feeding member and with a lower hearing which is .resilientl supported and tending to press said fee ing member against the charge of the machine. v

3. A wood grinding machine, as specified by claim 1, having at least one of the feeding members provided with an upper hearing arranged for'pivotal movement of said feeding which is provided with an adjustable spring tending to press said feeding member against the charge of the machine.

4. In a wood grinding machine, the commember and with a lower bearing bination of a grinding stone, with feedin ing stone and said feeding. members, said,

transmission gear comprising a hydraulic ciated therewith for varying a slip of said means 'asso-' 80 12 and exerts a controlling action upon a 1 coupling in dependence from the operating condition of said rinding stone.

5. A wood grin ing machine, as specified by claim 1, having a transmission gear interposed between the grinding stone and the feeding members, said transmission gear comprising a hydraulic sli(p couplin and regulatlng means associate therewit for varying the slip of said couplin in dependence from the operating eon Mom of said grinding stone.

6. In a wood grinding machine. the com gear interposed between said grinding stone and said feeding members, said transmission gear comprising a hydraulic slip coupling having two menihers mounted to rotate relatively to eachother, a liquid interposed between closely adjacent surfaces of said members of the slip coupling, and regulating means for varying the quantity of said liquid and therewith the relative speed of the two members of said coupling in dependence from variations of the operating condition of said grinding stone.

7. A wood grinding machine, as specified by claim 1, having a transmission gear interposed between the grinding stone and the feeding members, said transmission gear comprising a liquid coupling and regulating means for controlling the quantity of liquid in said coupling and therewith the slip of the latter in dependence from variations of the operating condition of said grinding stone.

8. A wood grinding machine, as specified by claim 4, in which the slip coupling consists of an outer rotor, an inner rotor mounted within the former and a liquid interposed between said rotors, the regulating means for said slip couplin being adapted to change the quantity of sa1d liquid and therewith the slip of said couplin 9. A wood grind ng machine, the combination of a driven spindle, a conveyer or feeding shaft, grinding elements mounted on said spindle and )roject-ing into one end of said conveyer or iecding shaft, pivotally mounted bearings at the outer end of said shaft, a threaded rotatable spindle having oppositely disposed threads at its opposite ends, frames mounted on'said threaded spindle. a bearing in each of said frames supported resilient-1y in a'lateral direction, and feeding members for conveying material to said grinding elements mounted at one end in said pivotal bearings and at the other end in said resilient bearings and forming limit ng walls of said conveyer or feeding shaft.

In testimony whereof, I have signed my name'to this specification at Breslau, Ger-- many, this 18 day of March, 1925.

GEORG NENZEL. 

